"The late-Pleistocene to Holocene Krasheninnikov volcano is comprised of two overlapping stratovolcanoes that were constructed within a 9 x 11 km Pleistocene caldera. Young lava flows from summit and flank vents descend into the caldera and down its outer flanks. The summit cones are situated along a NE-SW-trending fissure that has also produced zones of Holocene cinder cones extending 15-20 km beyond the caldera. Tephra deposits from the eruption forming Krasheninnikov caldera directly overlie a 39,000 before present (BP) tephra once thought to be related to the Krasheninnikov caldera-forming eruption but now thought to be associated with the formation of Uzon caldera (Florenskii 1988). Both the Southern and Northern cones are topped by 800-m-wide craters; the younger Northern Cone was constructed within a 2-km-wide caldera. Construction of the Southern Cone began about 11,000 years BP and lasted for about 4500 years. The Northern Cone was constructed during a cycle of similar length that began about 6500 years ago. The present eruptive cycle began about 600 years BP, but has included only two documented eruptions, the last about 400 years ago." -Smithsonian Volcano Archive